[section:replace_copy_if replace_copy_if]

[heading Prototype]

``
template<class ForwardRange, class OutputIterator, class UnaryPredicate, class Value>
OutputIterator replace_copy_if(const ForwardRange& rng, OutputIterator out,
                               UnaryPredicate pred, const Value& with_what);
``

[heading Description]

`replace_copy_if` copy every element `x` in `rng` such that the corresponding element in the output range `y` is `pred(x) ? with_what : x`.

[heading Definition]

Defined in the header file `boost/range/algorithm/replace_copy_if.hpp`

[heading Requirements]

* `ForwardRange` is a model of the __forward_range__ Concept.
* `ForwardRange` is mutable.
* `Value` is convertible to `ForwardRange`'s value type.
* `Value` is a model of the `AssignableConcept`.
* `OutputIterator` is a model of the `OutputIteratorConcept`.
* `UnaryPredicate` is a model of the `UnaryPredicateConcept`.

[heading Complexity]

Linear. `replace_copy_if` performs exactly `distance(rng)` evaluations of `pred`.

[endsect]